Stop motion apparatus for knitting machines

ABSTRACT

Stop motion apparatus for use with knitting machines wherein an electric motor is used to automatically re-set the stop motion after the same has been tripped by excessive tension in yarn controlled thereby, the tripping of the stop motion apparatus acting to automatically start the motor which then acts to automatically re-set the stop motion apparatus and to stop itself during a cycle of a single revolution of its output shaft, providing the stop motion apparatus has been re-set during such single revolution. If the stop motion apparatus is not re-set during the first of such cycle of operation of the motor, it will continue to operate to try to re-set the stop motion apparatus and to stop itself during each of successive ones of such cycles of operation of the motor.

United States Patent 1 Levin Mar. 5, 1974 STOP MOTION APPARATUS FOR KNITTING MACHINES 22 Filed: Oct. 16, 1972 211 App]. No.: 297,677

[52] US. Cl. 66/163, 66/146 [51] Int. Cl. D04b 35/12, D04b 27/12 [58] Field of Search..... 66/163, 158, 160,161,157, 66/125 R, 146; 57/81; 28/51.64; 200/5164;

FOREIGN PATENTS OR APPLICATIONS 559,435 2/1944 Great Britain 66/146 1,234,355 5/1960 France 66/125 R Primary ExaminerJames Kee Chi 1 t t o rrte y, A gem, or Firm Nathan W 57 ABSTRACT Stop motion apparatus for use with knitting machines wherein an electric motor is used to automatically reset the stop motion after the same has been tripped by excessive tension in yarn controlled thereby, the tripping of the stop motion apparatus acting to automatically start the motor which then acts to automatically re-set the stop motion apparatus and to stop itself during a cycle of a single revolution of its output shaft, providing the stop motion apparatus has been re-set during such single revolution. If the stop motion apparatus is not re-set during the first o'f such'cycle of operation of the motor, it will continue to operate to try to re-set the stop motion apparatus and to stop itself during each of successive ones of such cycles of operation of the motor.

10 Claims, 5 Drawing Figures PAIENTEDHAR 61914 3795.120

SHEET 1 OF 2 JW J FigJ Fig-2- 1 STOP MOTION APPARATUS FOR KNI'I'I'ING MACHINES The present invention relates generally to the art of knitting and particularly to yarn actuated stop motions, the present invention being directed to automatically operated stop motion apparatus for knitting machines which first acts to stop the machine when there is excess tension in yarn fed thereto and which then acts to re-set itself and to re-start the machine.

The present application is directed to an improvement in the apparatus disclosed in US. Pat. No. 3 ,726,1 1 3.

The control and operation of the apparatus of said Levin patent involves the use of both electricity and of compressed air, the latter being used to supply the force to automatically re-set the stop motion after the same has been tripped by excess tension in the yarns controlled thereby; While such use of both electricity and of compressed air is generally satisfactory, still, for reasons of economy, manufacture, ease of adjustment and use in mills where compressed air may not be readily available or is not available at all, it is desirable that electrically operated means be used to. automatically re-set the stop motion (instead of using compressed air) so that the control and operation of the apparatus involves only the use of electricity.

Accordingly, it is the principal object of the present invention to provide electrically operated means to supply the force to automatically re-set the tripped stop motion in the apparatus disclosed in said Levin patent.

It is also an object of the present invention to use an electric motor to supply the force to automatically reset the tripped stop motion in the apparatus disclosed in said Levin patent, the electric motor being started by the tripping of said stop motion and thereafter stopping itself after a single revolution of its output shaft, providing the stop motion has been re-set during such single revolution of the motor shaft.

With the above and other objects and advantages in view, as will become apparent from the following detailed description of a preferred embodiment of the invention shown in the accompanying drawings, the present invention resides in the elements of construction and arrangement of parts of the automatically operated and yarn actuated stop motion apparatus for knitting machines as illustrated, and as pointed out in the appended claims.

In the drawings:

FIG. I is a side elevationalview of one of the yarn arms of the stop motion apparatus in latched re-set position and of the electric motor re-setting means of the present invention in operative relation to the re-setting shaft upon which the yarn arms are pivotally supported, and the secondary shaft which engages and resets the yarn arms,

FIG. 2 is a front elevational view of portions of FIG. 1 showing the electric motor in operative relation to the re-setting shaft and to the secondary shaft,

FIG. 3 is a schematic view, generally similar to FIG. 1, showing several positions of the electric motor shaft, the re-setting shaft, and the secondary shaft during the re-setting operation,

FIG. 4 is a schematic view, generally similar to FIG. 3, showing the position of the parts when there is resistance to re-setting thestop motion, and

FIG. 5 is a schematic wiring diagram of the electrical circuit of the present apparatus including the arrangement for starting and stoppingthe electric motor after single revolutionsof its output shaft.

Only so much of said Levin patent need be referred to as is necessary to understand how the present electrically operated resetting means works therewith in place of the compressed air operated re-setting means shown therein. In the patent, re-setting of yarn arms 34, from their dotted line (unlatched) to their full line (latched) positions of FIGS. 3 and 6 is accomplished by turning re-setting shaft 26 approximately from its normal inoperative position of FIG. 3 to its fully operative position of FIG. 6, such movement of shaft 26 being made by compressed air (when turned on) via air cylinder 48, FIG. 5, chain 44 and gear 40 fast on shaft 26. As shaft 26 is turned, secondary shaft 38, fixedly spaced from shaft 26 by brackets 42, moves to engage tripped arms 34 to re-set the same by pivotally moving them about shaft 26 to their full line latched position. Arms 34 are moved to their unlatched position by excess tension on the yarns Y. In unlatched tripped position of the arms, pin 34a is disengaged from latch 32 which then makes electrical contact with strip 28b. In latched reset position of the arms, the pin 34a' is engaged with latch 32 which then moves out of electrical contact with strip 28b. The compressed air is automatically turned on when such electrical contact is made and is automatically turned off when it is broken. Shaft 26 is returned to its normal position of rest by weight 46 when the compressed air is turned off,

The compressed air operated means of said Levin patent to turn re-setting shaft 26 is replaced in the present application by an electric motor operatively related to the same re-se'tting shaft to similarly turn the same.

' Referring now to the present drawings, only so much of the apparatus of said Levin patent has been shown therein as is necessary to understand how the present re-setting means operates therewith. The apparatus which is common to the present disclosure and to said Levin patent will be described first and then the present electric re-setting means will be set forth I One of a spaced pair of upright parallel support members is indicated at 20 in FIG. I with its upper end suitably apertured to supportedly receive therein a longitudinally extending fixed support shaft 22; Each upright 20 is slotted, as at 200, to intersectthe shaft receiving aperture whereby shaft 22 may be clampingly secured in fixed'position in each support 20 by suitably placed screw 20b extending across slot 20a. I

Shaft 22in turn provides 'a support for a member of spaced brackets one of which is shown at 24. Each such bracket is provided with a suitable aperture to'receive shaft 22 therein, the bracket being slotted at 24a to intersect the shaft receiving aperture whereby the bracket may be clamped'in place uponshaft 22 by suitably placed screw 24b extending across slot 24a. Each bracket 24, at one end thereof, is suitablyap'ertured to 'rotatably support a horizontally disposed shaft 26' sides of tail ends 24d of brackets 24 by suitably placed screws 28a extending through tail ends 24d into threaded engagement with bar 28. Bar 28 provides support for a series of spaced upright control boxes, one of which is shown at 30, and each of which is secured to the bar by a suitably placed screw 30a extending through the bar into threaded engagement with the control box. Bar 28, on the side thereof facing shaft 22, is provided'with a strip 28b of electrically conductive material for substantially its full length, the strip being suitably secured to and electrically insulated from the bar. The bar is electrically grounded and a suitable electrically conductive connection extends from strip 28b to the stop motion circuit of the machine and present apparatus.

Each box 30, of generally rectangular shape, is set transversely on bar 28 and is provided at its forward end with a centrally disposed vertical slot extending therethrough. A vertically extending latch 32 is disposed in the slot, the latch being pivotally supported upon pivot pin 32a extending through the slotted portion of the box and through the latch itself, lower portion 32b of the latch extends below the box and is disposed opposite strip 28b on bar 28. When latch 32 is held in its full line position of FIG. 1, portion 32b thereof is spaced from strip 28b, whereas when latch 32 is in its dotted line position, portion 32b thereof is in electrical contact with strip 28b When latch 32 is in dotted line position portion 32)) thereof is urged into contact with strip 28b by a compression spring (not shown) disposed in a suitable lengthwise extending aperture in box 30, the spring being in contact with the latch above its pivot 32a. A screw 30b is threadedly engaged into the open end of the spring receiving aperture in the box to adjustably tension the spring. Latch 32 is retained in its full line position by a latching pin 34a extending laterally from handle portion 34b of pivotably movable yarn arm 34. Latch pin 34a is caught in and retained by an undercut notch formed in the latch thereby to hold the latter and the re-set arm in their latched positions.

Generally, an arm 34 is provided for each box 30, however, if desired a pair of arms 34 may be operatively related to each box thereby to reduce the number of boxes required. Each arm 34 comprises a longitudinally extending handle 34b, preferably of rectangular cross section, and tube 34c suitably secured in and extending from one end of the handle. The tube is provided with a cut out 34d, adjacent its free end, through which yarn Y, extending from a cone thereof, enters the tube and extends to and passes out of its free end to the feed of the machine using the same. Handle 34b is provided with a suitable aperture at the tube end thereof whereby arm 34 is rotatably supported on shaft 26.

A secondary shaft 38 is secured in fixed spaced parallel relation to shaft 26 by rocker arms 42 spaced along and between these shafts. Each rocker arm has spaced apertures within which to receive shafts 26 and 38 and is slotted, as at 42a, to intersect the apertures whereby the shafts mey be fixedly clampingly engaged in the bracket by suitably placed screw 42b extending across slot 42a. Thus angular movement of shaft 26 causes shaft 38 to move correspondingly about the axis of shaft 26. Rocker arm 42 is adjustable angularly on shaft 26 and is placed so that shaft 38 may move approximately 90 between its full and dotted line positions of FIG. 1 when shaft 26 is turned a like number of degrees.

The normal operating position of yarn arm 34 is shown in full lines in FIG. 1 wherein the arm, via latch pin 34a, maintains the portion 32b of latch 32 in spaced relation from strip 28b, and, at the same time, the latches maintain the yarn arm in normal operating position. Should there be excess tension on yarn Y it will tend to turn arm 34 in clockwise direction, FIG. I, and, if such tension is sufficient to overcome the force ex erted by latch 32 on latch pin 34a, the arm will be released from the latch and will be turned in clockwise direction. The arm may turn about to its dotted line position of FIG. 1 or to any position short thereof. Latch 32 will move to its dotted line position and make electrical contact with strip 28b to stop the machine, as will be set forth in connection with FIG. 5, The shaft 38, full line, may serve as a limit stop for movement of arm 34 by engaging handle 34b, dotted line. Then as shaft 38 is caused to move to its dotted line position by movement of shaft 26, arm 34 is returned to its full line position and is latched therein when latch 32 engages and holds pin 34a, at the same time latch 32 moves away from strip 28b to break the electrical connection therebetween.

The present electrical means to turn shaft 26 includes a rocker arm 44, generally similar to rocker arm 42, which is fixedly clampingly engaged about shaft 26 and about a relatively short pin 44a, spaced from shaft 26, which extends through rocker arm 44 and into freely rotative engagement with suitable apertures in spaced vertically extending arms 46a of a U-shaped bracket 46. in threaded engagement with and extending centrally from the bottom of bracket 46 is a lengthwise extending push-pull rod 48, the rod being adjustably screwed into the bracket and being locked in adjusted position by nut 48a threaded upon the rod and in locking contact with the bracket.

The rod 48 extends freely through suitable apertures in spaced horizontally extending arms 50a, 50b of a second U-shaped bracket 50, the bracket itself having a shoulder screw 52 in threaded engagement with and extending centrally from the base thereof. The shoulder screw extends rotatably through a suitable aperture in one end of a relatively short motor crank arm 54, the arm having an aperture in its other end within which is fixedly secured output shaft 560 of motor 56. A lengthwise positionable stop 48b is adjustably secured on rod 48 in spaced relation to and above bracket 50 while a second lengthwise positionable stop 480 is adjustably secured on the rod adjacent to and below the bracket. Suitable set screws extending through stops 48c and 48b into engagement with rod 48 are provided to hold the stops in adjusted positions. A coiled compression spring 58, of suitable length, number of coils, and of wire size, is placed over rod 48 and is compressed between stop 4819 and bracket 50a, the extent of the compression being adjustable by means of stop 48b. The spring normally causes stop 480 to remain in contact with bracket 50b.

Motor 56, of suitable power, is preferably geared so that its output shaft makes a single revolution in about four seconds. The time per revolution is not critical and may be greater or less than four seconds depending upon how long a time is desired within which to re-set the stop motion. Motor 56 may be suitably secured to L-shaped bracket 56b the vertical portion of which is suitably secured to upright 20. Resting upon and suitably secured to the horizontal portion of bracket 56b, directly below rod 48, is a microswitch 60 having a pivotable switch arm 60a positioned so as to be engaged and depressed by end 48d of the rod when the latter is in its position of rest, as in FIGS. 1 and 2. Micro-switch 60 is of the type which is in the on position when its switch arm 60a is raised, as in FIGS. 3 and 4 with the end of rod 48 removed therefrom, and is in the off position when its switch arm is lowered, as in FIGS. 1 and 2 with the end of rod 48 depressing the same. Micro-switch 60 is wired to motor 56 to start the same in its on position and to stop the same in its off position.

The electrical circuit is such that, with the parts as in FIGS. 1 and 2 with micro-switch 60 in the off position and latch 32 spaced from strip 2812 (the motor being at rest), when the stop motion is tripped by turning arm 34 to unlatched position, this causes contact to be made between latch 32 and strip 28b whereby motor 56 is energized and its shaft 56a turns in direction of arrow A. Movement of shaft 56a, via arm 54, shoulder screw 52, bracket 50, spring 58, and stop 48b, causes end 48d of the rod to move away from switch arm 60a, FIG. 3, whereby the latter rises to its on position thereby also being in position to energize the motor. When the motor, via rod 58 and bracket 44, acts to re-set arm 34, the latch 32 becomes spaced from strip 28b to break its connection to the motor, however the motor continues to turn because of the on position of micro-switch 60 until a full revolution of the motor output shaft has been made and end 48d of the rod engages with and depresses the switch arm to its off position, thereby stopping the motor after one turn of its output shaft. Thus the motor is started by the tripping of the stop motion and is stopped after one turn of its output shaft. During such turn the stop motion is re-set by the motor.

As the motor turns 90 from its position of FIG. 1 to that of FIG. 3, rod 48 moves away from the microswitch and at the same time is raised to turn brackets 42, 44 and shaft 26 approximately 45 in which position 44 is approximately horizontal. When the motor has turned 180 the rod has been raised to its uppermost position wherein it is vertical and at the same time brackets 42, 44 and shaft 26 have been turned a second 45 to their dotted line position in FIG. 3. This turning of shaft 26 through 90 acts to re-set the stop motion arm 34 as previously explained. Further movement of the motor to 270 returns brackets 42, 44 to approximately their full line positions of FIG. 3, and movement of the motor through 360 returns the parts to their position of FIG. 1 with rod 48 closing the micro-switch to stop the motor. The motor is preferably supplied with a brake to prevent undesirable overtravel of the output shaft when the micro-switch is turned off.

Rod 48, bracket 50 and shoulder screw 52 move pivotally about crank arm 54 as the latter is turned by the motor shaft. Bracket 46 moves pivotally about pin 44a as the rod is raised and lowered. Rod 48 is yieldingly pushed upwardly via bracket arm 50a acting on compressed spring 58, and is positively pulled downwardly via bracket arm 50b acting on stop 480. In the event that there is sufficient resistance to turning of shaft 26, for any reason, such as the yarn being caught, then as rod 48 is raised the spring 58 will be further compressed and bracket 50 will be moved along the rod, as

appears in FIG. 4.. Under these conditions shaft 26 will not be turned sufficiently to re-set stop motion. arm 34 and contact between latch 32 and strip 28b will be maintained. So long as such contact is maintained the motor will continue to turn even when the micro-switch is opened and closed as the end 48d of rod 48 moves through the zero position. The one revolution cycle of the motor will be repeated so long as latch 32 remains in contact with strip 28b. After one or more of such cycles the apparatus may act to reset arm 34 in which case the motor will then stop, or if the yarn remains caught and the apparatus should not re-set itself, then operator help would be required. Stop 48b may be adjusted as desired to determine the initial compression of spring 48, such adjustment taking into account the breaking strength of the yarns controlled by the stop motion.

As indicated schematically in FIG. 5, the motor used for operating the knitting machine is shown at M and part of its motor circuit at Ma, the latter including a solenoid controlled starting switch S which, in its full line position, causes the motor to operate the machine. Connected to the switch S is the usual stop motion circuit of the machine of which a portion thereof is shown at C and contains a power source B. The closing of the circuit lines of C by any of the usual stop motion devices of the machine will energize the solenoid of switch S to move the latter to its dotted line position and to stop the machine. Connected into the stop motion circuit of the machine is the circuit of the present re-setting means which includes electrical contacts between latch 32 and strip 28b and in the micro-switch 60. This latter circuit is normally open since latch 32 is normally spaced from strip 28b and since switch arm 60a is normally in its opened position, as shown by the full lines 32 and 60a in FIG. 5. Assuming the machine to be running with switch S in closed position and the other switches in open position, when a yarn arm 34 is tripped contact is made between latch 32 (in dotted line position) and strip 28b to energize switch S to open the same thereby stopping the machine and at the same time to start the motor 56. Shortly thereafter, as motor 56 turns, micro-switch 60 is also closed (in dotted line position). Thereafter, when the motor has turned about contact is broken between latch 32 and strip 2817 as arm 34 is re-set, and the motor continues to turn until stopped at the end of one revolution by the opening of the micro-switch by the end 48d of rod 48. The opening of the two motor switches will open the circuit and switch S is permitted to return to closed position to restart the motor M to run the machine. If desired, one or more relays may be placed in the circuit to delay the start of the motor 56 a short time until the machine has fully stopped, and/or to delay the re-starting of the machine until a short time after the motor 56 has stopped. It will be understood that after the resetting of arm 34 there will normally be a short delay (equal to one half the cycle time) until the micro-switch is opened to stop the motor 56. Electrically energized means, such as a solenoid or the like, may be used in place of the motor. An adjustable slip clutch may be used with the motor to yieldingly apply the force thereof to shaft 26. Shaft 26 may be turned in one direction by the electrical means and may be returned by other means, such as a return spring.

I claim 1. Stop motion apparatus for a knitting machine having at least one yarn fed thereto when it is in operation, said apparatus having at least one arm for the feeding of said yarn to said machine, said arm being movable between a first and a second position, said arm being movable to its said second position when said yarn is excessively tensioned thereby to stop the operation of said machine as well as the feeding of said yarn, and said arm being movable to and re-set in its said first position thereby to restart the operation of said machine as well as the feeding of said yarn, and the improvement which consists of electrically operated means to exert electrical force upon said arm after its said movement to said second position thereof to re-set the same in its said first position, said means being electrically energized to exert its said force as a result of said movement of said arm by said excessively tensioned yarn.

2. The apparatus of claim 1 wherein said re-set means automatically causes itself to become inoperative after said arm has been re-set thereby, and wherein said reset means remains inoperative while said arm remains in said re-set position.

3. The apparatus of claim 1 wherein said re-set means is an electric motor, wherein said movement of said arm by said excessively tensioned yarn causes said motor to start, and wherein said motor is adapted to automatically re-set said arm.

4. The apparatus of claim 3 wherein said electric motor is adapted to automatically stop itself after said arm has been reset thereby.

5. The apparatus of claim 3 wherein said motor is adapted to automatically re-set said arm during one revolution of its output shaft.

6. The apparatus of claim 4 wherein said motor is adapted to automatically re-set said arm and to automatically stop itself during one revolution of its output shaft.

7. The apparatus of claim 3 wherein the force exerted by said motor upon said arm to re-set the same is yieldingly applied thereto.

8. The apparatus of claim 5 wherein said arm is pivotally mounted for rockable movement back and forth between its said first and second positions, and wherein said motor output shaft is connected to said arm in such manner that a single revolution of said motor output shaft causes said arm to be rocked from its said second to its said first position.

9. The apparatus of claim 3 wherein an electrical circuit is provided, wherein said circuit can be placed in open and in closed condition, wherein a micro-switch is provided, wherein said motor, said micro-switch and said arm are operatively related to said circuit in such manner that said motor is stopped when said circuit is open and that said motor is operated when said circuit is closed, wherein said circuit is closed to operate said motor by said micro-switch in its on position and by said arm in its said second position, and wherein said circuit is open to stop said motor when said microswitch is in its off position at the same time that said arm is in its re-set position.

10. The apparatus of claim 9 wherein said motor is adapted to automatically re-set said arm and to automatically stop itself during one revolution of its output shaft, wherein said motor in stopped condition causes said micro-switch to be placed in its off position, wherein said micro-switch is caused to be placed in its on position by said motor as it operates, and wherein said microswitch is caused to be placed in its off position by said motor as its said output shaft completes said one revolution thereof. 

1. Stop motion apparatus for a knitting machine having at least one yarn fed thereto when it is in operation, said apparatus having at least one arm for the feeding of said yarn to said machine, said arm being movable between a first and a second position, said arm being movable to its said second position when said yarn is excessively tensioned thereby to stop the operation of said machine as well as the feeding of said yarn, and said arm being movable to and re-set in its said first position thereby to restart the operation of said machine as well as the feeding of said yarn, and the improvement which consists of electrically operated means to exert electrical force upon said arm after its said movement to said second position thereof to re-set the same in its said first position, said means being electrically energized to exert its said force as a result of said movement of said arm by said excessively tensioned yarn.
 2. The apparatus of claim 1 wherein said re-set means automatically causes itself to become iNoperative after said arm has been re-set thereby, and wherein said re-set means remains inoperative while said arm remains in said re-set position.
 3. The apparatus of claim 1 wherein said re-set means is an electric motor, wherein said movement of said arm by said excessively tensioned yarn causes said motor to start, and wherein said motor is adapted to automatically re-set said arm.
 4. The apparatus of claim 3 wherein said electric motor is adapted to automatically stop itself after said arm has been reset thereby.
 5. The apparatus of claim 3 wherein said motor is adapted to automatically re-set said arm during one revolution of its output shaft.
 6. The apparatus of claim 4 wherein said motor is adapted to automatically re-set said arm and to automatically stop itself during one revolution of its output shaft.
 7. The apparatus of claim 3 wherein the force exerted by said motor upon said arm to re-set the same is yieldingly applied thereto.
 8. The apparatus of claim 5 wherein said arm is pivotally mounted for rockable movement back and forth between its said first and second positions, and wherein said motor output shaft is connected to said arm in such manner that a single revolution of said motor output shaft causes said arm to be rocked from its said second to its said first position.
 9. The apparatus of claim 3 wherein an electrical circuit is provided, wherein said circuit can be placed in open and in closed condition, wherein a micro-switch is provided, wherein said motor, said micro-switch and said arm are operatively related to said circuit in such manner that said motor is stopped when said circuit is open and that said motor is operated when said circuit is closed, wherein said circuit is closed to operate said motor by said micro-switch in its on position and by said arm in its said second position, and wherein said circuit is open to stop said motor when said micro-switch is in its off position at the same time that said arm is in its re-set position.
 10. The apparatus of claim 9 wherein said motor is adapted to automatically re-set said arm and to automatically stop itself during one revolution of its output shaft, wherein said motor in stopped condition causes said micro-switch to be placed in its off position, wherein said micro-switch is caused to be placed in its on position by said motor as it operates, and wherein said microswitch is caused to be placed in its off position by said motor as its said output shaft completes said one revolution thereof. 